"We put a layer of asphalt over the roadway and then come over with rocks or small pebbles to go over that, and what that does (is) it provides something of a new surface," said Val Lopez, of TxDOT. "It provides an additional protective seal over the roadway."

But driving over the new surface is much louder and feels like driving over rough sandpaper.

"I just know that it is louder," said Jerry Bianchi, who drives 51 miles to work from his Sanger home. "I just thought it wasn't quite completed."

He said the road looks like gravel with tar poured over it.

"What motorists may be hearing is a little additional road noise that, eventually, as those rocks settle into the asphalt, will begin to soften," Lopez said.

He said using the other process will prevent moisture from seeping down into the structure of the road, something that eventually causes potholes and can result in bigger road failures in the future.

The seal-coat process is also much cheaper than tearing up the old surface and putting down fresh asphalt or concrete. The project along Texas 121 cost just $220,000, compared to more than $1 million for the other, more traditional way.

"It gives us probably the best use of tax dollars, because it's roughly five or six times more expensive to go build and overlay it," Lopez said.